ASF Italy: Sardinia reports outbreak of genotype II

The outbreak occurred on a farm in Dorgali, in Nuoro province, in the middle of the island at the coast facing the Italian mainland. The farm was a closed-cycle facility, housing 13 pigs, of which 3 had died. The others were culled. This all happened as from 19 September 2023 – but was only reported to the World Organization for Animal Health (WOAH) on January 12. As a consequence of the outbreak, the Italian authorities started a stringent research and concluded that the virus had not spread.

Unique ASF situation at Sardinia

In itself it is no surprise that ASF virus is found on Sardinia, as it is the only place in Europe where ASF virus has been endemic for decades. It is a leftover of a wave of ASF outbreaks in mostly southern Europe in the 1960s until the early 1990s, which also affected Spain and Portugal. That wave was caused by ASF virus, genotype I. As a consequence of the endemic situation, from time to time outbreaks of genotype I get found on Sardinia, but this doesn’t constitute “news”, as ASF is considered endemic.

Now Italy also confirmed genotype II on the island, most likely as a consequence of infected meat products that was brought from the mainland. On the mainland, genotype II has been found since early 2022 in 4 different locations, in both domestic pigs as well as wild boar populations.

ASF situation description

In a report to the WOAH, the Italians wrote: “As is known, the ASF virus was already present in Sardinia with genotype I, while genotype II is the one circulating in mainland Italy since January 2022.

“After the confirmation of the presence of the genotype II virus, absent from the island until then, an extensive monitoring and tracing activity was implemented to understand the origin of the virus and evaluate its possible spread.

“All the checks gave negative results (200 farms were checked within a 10 km radius, passive and active surveillance were reinforced to monitor the possible introduction of the virus into the surrounding environment, and 300 wild boar were tested), and based on the epidemiological investigation an entry was established of the virus in the regional territory on 6 September.

“As required by current regulations, immediately after confirmation all remaining animals were killed and destroyed and protection and surveillance zones were established in accordance with Regulation 687/2020.”

Both ASF genotypes present in Italy

Even though the presence of genotype II appears to have been a one-off occurrence, it made Sardinia one of the few places in the world where both well-known ASF genotypes co-existed. Apart from Sardinia, this situation has been reported from China since 2021, and in a few countries in Africa, i.e. Zambia and Nigeria.